Battery pack and connecting circuits of battery modules

ABSTRACT

A battery pack and connecting circuits of battery modules. The battery pack includes a plurality battery modules connected in series, wherein each battery module is provided with a connecting circuit. When the battery module operates normally, the connecting circuit serially connects the current battery module to the previous battery module and the succeeding battery module. When the battery module operates abnormally, the connecting circuit selectively disconnects the battery module, and if it disconnects the current battery module, it directly connects the previous battery module and the succeeding battery module in series. When a battery module is damaged abnormal, the current damaged battery module can be disconnected from the series battery pack and bypassed. As such, the previous battery module may be directly connected with the succeeding battery module, ensuring the normal connection of the series circuit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Nonprovisionalapplication Ser. No. 14/967,359, filed Dec. 14, 2015, which is acontinuation of U.S. Nonprovisional application Ser. No. 14/883,599,filed Oct. 14, 2015, which claims priority to U.S. ProvisionalApplication No. 62/150,848, filed on Apr. 22, 2015, and U.S. ProvisionalApplication No. 62/133,991, filed on Mar. 16, 2015, the disclosures ofwhich are hereby incorporated by reference in their entireties for allpurposes.

BACKGROUND

Exemplary embodiments of the present disclosure relate to a battery packof an electric vehicle, and more particularly, to a battery pack of anelectric vehicle which is capable of automatically bypassing a faultedbattery module.

Environmental-friendly and energy-saving new electric vehicles, whichbelong to a new field of future automobile development and will begreatly developed in the future, have a broad market prospect. Thebattery charge and discharge technology is key in the development ofelectric vehicles.

In general, the battery pack of an electric vehicle is formed byconnecting a plurality of batteries (e.g., modules) in series. Forexample, an electric vehicle may have a total of 10 battery modules,each of which provides a voltage output of 40V. As such, the batterymodules in series would provide a total voltage output of 400V. However,in such a series battery module structure, when one or more batterymodules fail, the series circuit cannot be connected. As such, the wholebattery pack cannot work normally.

SUMMARY

In view of the above problems, aspects of the present disclosure areintended to provide a battery pack capable of automatically bypassing afaulted battery module, which may provide advantages such as improvingthe safety of an electric vehicle.

According to a first aspect of the disclosure, a battery pack isprovided. The battery pack may include a plurality of battery modulesconnected in series, wherein each battery module is connected with aconnecting circuit. In embodiments, when the battery module worksnormally, the connecting circuit serially connects a front batterymodule and a subsequent battery module through a current battery module.In embodiments, when the current battery module works abnormally, theconnecting circuit can optionally disconnect or not disconnect thecurrent battery module. In embodiments, when the current battery moduleis disconnected, the front battery module and the subsequent batterymodule thereof are directly connected in series. The battery pack mayfurther include a plurality of driving circuits, which are respectivelyconnected with the connecting circuits and used for controlling theconnecting circuits to disconnect the current battery modules.

In some embodiments, each battery module in the battery pack is providedwith a connecting circuit. In embodiments, the control circuit maydisconnect the current abnormal battery module from the series batterypack when the current battery module is abnormal. In doing so, thecurrent battery module is bypassed and the front battery module and thesubsequent battery module thereof are directly connected together.

In some embodiments, additional bypasses may be implemented, e.g. if theforward and/or subsequent batteries enter an abnormal state.

Embodiments of the disclosure may provide advantages, such as ensuringnormal communication of the series circuit, reducing the probability ofroadside assistance, lowering maintenance costs, and providing anopportunity to a driver of the vehicle to drive to the nearestmaintenance station for overhauling.

Additional features, advantages, and embodiments of the invention may beset forth or apparent from consideration of the following detaileddescription, drawings, and claims. Moreover, it is to be understood thatboth the foregoing summary of the invention and the following detaileddescription are exemplary and intended to provide further explanationwithout limiting the scope of the invention claimed. The detaileddescription and the specific examples, however, indicate only preferredembodiments of the invention. Various changes and modifications withinthe spirit and scope of the invention will become apparent to thoseskilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the detailed description serve to explain the principlesof the invention. No attempt is made to show structural details of theinvention in more detail than may be necessary for a fundamentalunderstanding of the invention and various ways in which it may bepracticed. In the drawings:

FIG. 1 is a schematic diagram illustrating a circuit structure of abattery pack according to an embodiment of the disclosure.

FIG. 2A is a schematic diagram illustrating a connecting circuit of abattery module in a normal state according to an embodiment of thedisclosure;

FIG. 2B is a schematic diagram illustrating a connecting circuit of abattery module in an abnormal state according to an embodiment of thedisclosure;

FIG. 3A is a schematic diagram illustrating an internal structure of acontrol device according to an embodiment of the disclosure;

FIG. 3B is a schematic diagram illustrating a structure of a drivingcircuit according to an embodiment of the disclosure;

FIG. 4 is a schematic diagram illustrating connecting circuits when acertain battery module of the battery pack fails according to anembodiment of the disclosure; and

FIG. 5 is a flow schematic diagram illustrating fault processingstrategies according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Various example embodiments of the present disclosure will be describedbelow with reference to the drawings constituting a part of thedescription. It should be understood that, although terms representingdirections are used in the present disclosure, such as “front”, “rear”,“upper”, “lower”, “left”, “right”, and the like, for describing variousexemplary structural parts and elements of the present disclosure, theseterms are used herein only for the purpose of convenience of explanationand are determined based on the exemplary orientations shown in thedrawings. Since the embodiments disclosed by the present disclosure canbe arranged according to different directions, these terms representingdirections are merely used for illustration and should not be regardedas limiting. Wherever possible, the same or similar reference marks usedin the present disclosure refer to the same components.

Unless defined otherwise, all technical terms used herein have the samemeanings as commonly understood by one of ordinary skill in the art towhich the invention pertains. The embodiments of the invention and thevarious features and advantageous details thereof are explained morefully with reference to the non-limiting embodiments and examples thatare described and/or illustrated in the accompanying drawings anddetailed in the following description. It should be noted that thefeatures illustrated in the drawings are not necessarily drawn to scale,and features of one embodiment may be employed with other embodiments asskilled artisan would recognize, even if not explicitly stated herein.Descriptions of well-known components and processing techniques may beomitted so as to not unnecessarily obscure the embodiments of theinvention. The examples used herein are intended merely to facilitate anunderstanding of ways in which the invention may be practiced and tofurther enable those of in the art to practice the embodiments of theinvention. Accordingly, the examples and embodiments herein should notbe construed as limiting the scope of the invention, which is definedsolely by the appended claims and applicable law. Moreover, it is notedthat like reference numerals reference similar parts throughout theseveral views of the drawings.

FIG. 1 is a schematic diagram illustrating a circuit structure of abattery pack according to an embodiment of the disclosure.

As shown in FIG. 1, the battery pack 100 may include battery modules,connecting circuits, driving circuits, monitoring circuits, a controldevice and the like. Specifically, the battery pack 100 may include aplurality of battery modules 101.1, 101.2, 101.3, . . . , 101.i, . . . ,101.N. Further, the battery modules 101.1, 101.2, 101.3, . . . , 101.i,. . . , 101.N may be respectively provided with connecting circuits111.1, 111.2, 111.3, . . . , 111.i, . . . , 111.N and monitoringcircuits 141.1, 141.2, 141.3, . . . , 141.i, . . . , 141.N. Theconnecting circuits 111.1, 111.2, 111.3, . . . , 111.i, . . . , 111.Nmay connect the battery modules in series to form a power supply circuitof the battery pack 100. In some embodiments, the monitoring circuits141.1, 141.2, 141.3, . . . , 141.i, . . . , 141.N may respectivelymonitor the working states of the battery modules and transmit theworking states to a control device 130.

In some embodiments, the connecting circuits 111.1, . . . , 111.N arerespectively controlled by driving circuits 121.1, 121.2, 121.3, . . . ,121.i, . . . , 121.N. For example, the driving circuits 121.1, 121.2,121.3, . . . , 121.i, . . . , 121.N may respectively control theconnecting and disconnecting of the connecting circuits 111.1, 111.2,111.3, . . . , 111.i, . . . , 111.N, so that a corresponding batterymodule 101.i can be connected into or disconnected from the seriescircuit. The driving circuits 121.1, 121.2, 121.3, . . . , 121.i, . . ., 121.N may be controlled by the control device 130. In someembodiments, the control device 130 judges or analyzes whether thebattery modules 101.1, 101.2, 101.3, . . . , 101.i, . . . , 101.N areoperating in an abnormal state or faulted, according to monitoringsignals of the monitoring circuits 141.1, 141.2, 141.3, . . . , 141.i, .. . , 141.N on the battery modules 101.1, 101.2, 101.3, . . . , 101.i,101.N. If a certain battery module 101.i (e.g., the battery module101.2) is operating in an abnormal state (as shown in FIG. 4), thecontrol device 130 selectively disconnects or does not disconnect theabnormal battery module 101.2, according to specific conditions of theabnormality.

In some embodiments, if the control device 130 selects to disconnect thebattery module 101.2 that is operating in the abnormal state, it sends adisconnecting signal to the corresponding driving circuit 121.2. Assuch, the driving circuit 121.2 is initiated and a connecting switch inthe connecting circuit 111.2 is turned off, so that the series circuitbypasses the faulted battery module 101.2 and directly connects thenormal previous battery module 101.1 with the normal succeeding batterymodule 101.3 adjacent to the battery module 101.2 in series. Exemplarystructures of the connecting circuit 111.2 are shown as FIG. 2A and FIG.2B.

FIG. 2A is a schematic diagram illustrating a connecting circuit of abattery module operating in a normal state according to an embodiment ofthe disclosure. Taking the battery module 101.2 in FIG. 1 as an example,as shown in FIG. 2A, the battery module 101.2 is provided with aconnecting circuit 111.2, an positive terminal 208.2 and a negativeterminal 209.2. In some embodiments, the connecting circuit 111.2 isprovided with a first switch 201.2, a second switch 202.2, and a bridge203.2. The bridge 203.2 may be provided with a first end point 204.2 onone side close to the first switch 201.2, and a second end point 206.2on the side close to the second switch 202.2. In some embodiments, thefirst switch 201.2 and the second switch 202.2 may be single-poledouble-throw switches, and may be respectively provided with a firstmoving end 205.2 and a second moving end 207.2.

One end of the first moving end 205.2 is fixed to form a fixed endpoint, and the other end of the first moving end 205.2 is a movable endpoint, which may be selectively connected to the positive terminal 208.2of the battery module 101.2 or the first end point 204.2 of the bridge203.2. Similarly, one end of the second moving end 207.2 is fixed toform a fixed end point, and the other end of the second moving end 207.2is a movable end point, which may be selectively connected to thenegative terminal 209.2 of the battery module 101.2 or the second endpoint 206.2 of the bridge 203.2. The fixed end point of the first movingend 205.2 of the battery module 101.2 is connected with the fixed endpoint of the second moving end of the previous battery module 101.1. Inaddition, the fixed end point of the second moving end 207.2 of thebattery module 101.2 is connected with the fixed end point of the firstmoving end of the succeeding battery module 101.3 (as illustrated inFIG. 4). It should be noted that the terminals described herein mayswitch functions, e.g. between anode or cathode, depending on whetherthe batteries are charging or discharging.

When the battery module 101.2 is operating in a normal state, themovable end point of the first moving end 205.2 of the first switch201.2 is connected to the positive terminal 208.2 of the battery module101.2. Further, during normal operation, the movable end point of thesecond moving end 207.2 of the second switch 202.2 is connected to thenegative terminal 209.2 of the battery module 101.2. As such, in thiscase, when both the previous battery module 101.1 and the succeedingbattery module 101.3 are operating normally (e.g., without faulting),the connecting circuit 111.2 connects the positive terminal 208.2 of thebattery module 101.2 with the negative terminal 209.1 of the previousbattery module 101.1 (see FIG. 4). In addition, in this case, thenegative terminal 209.2 of the battery module 101.2 is connected withthe positive terminal 208.3 of the succeeding battery module 101.3 (seeFIG. 4). Accordingly, the current battery module 101.2 is connected intothe series circuit of the battery pack 100.

FIG. 2B is a schematic diagram illustrating a connecting circuit of abattery module operating in an abnormal state according to an embodimentof the disclosure. Taking the battery module 101.2 as an examplelikewise, as shown in FIG. 2B, when the battery module 101.2 is inabnormal state (e.g., a fault in battery module 101.2 exists), themonitoring circuit 141.2 thereof transmits a state signal to the controldevice 130 (see FIG. 1). When the control device 130 or analyzes thatthe battery module 101.2 needs to be disconnected, the control device130 transmits a disconnecting signal to the corresponding drivingcircuit 121.2. Further, upon receiving the disconnecting signal, thedriving circuit 121.2 starts working to drive the first 201.2 so thatthe movable end point of the first moving end 205.2 thereof is connectedwith the end point 204.2 of the bridge 203.2. In addition, uponreceiving the disconnecting signal, the driving circuit 121.2 startsworking to drive the second switch 202.2 so that the movable end of thesecond moving end 207.2 thereof is connected with the second end point206.2 of the 203.2.

In this case, when both the previous battery module 101.1 and thesucceeding battery module 101.3 are operating in a normal state, theconnecting circuit 111.2 disconnects the positive terminal 208.2 of thecurrent battery module 101.2 from the negative terminal 209.1 of theprevious battery module 101.1. Additionally, the connecting circuit111.2 disconnects the negative terminal 209.2 of the current batterymodule 101.2 from the positive terminal 208.3 of the succeeding batterymodule 101.3. As such, the connecting circuit 111.2 connects thenegative terminal 209.1 of the previous battery module 101.1 with thefirst end point 204.2 of the bridge 203.2 in the connecting circuit111.2 of the current battery module 101.2. Further, the connectingcircuit 111.2 connects the positive terminal 208.3 of the succeedingbattery module 101.3 with the second end point 206.2 of the bridge203.2, so that the previous battery module 101.1 and the succeedingbattery module 101.3 are directly connected to the series circuit of thebattery pack 100 by the bridge 203.2. According to aspects of thedisclosure above, the abnormal current battery module 101.2 may bebypassed and battery pack 100 may continue to operate.

It will be appreciated that the embodiments in FIG. 2A and FIG. 2Bmerely describe the connecting circuit of a battery module by taking thebattery module 101.2 as an example. In embodiments, the structure andthe working principle of the connecting circuit of any battery module101.i may be identical or similar to those of the battery module 101.2.Additionally, in some examples, a bypass may be formed by disconnectingone of the positive or negative terminals.

FIG. 3A is a schematic diagram illustrating an internal structure of thecontrol device 130 according to an embodiment of the disclosure. In someembodiments, the control device 130 is provided with a batterymonitoring unit 310, a processor (CPU) 320, an input/output (I/O) port330 and the like. The battery monitoring unit 310, which is connected tothe monitoring circuits 141.1, 141.2, 141.3, . . . , 141.i, . . . ,141.N and the processor (CPU) 320, receives monitoring signals of themonitoring circuits 141.1, 141.2, 141.3, . . . , 141.i, . . . , 141.Nand sends the monitoring signals to the processor (CPU) 320 forprocessing. The processor (CPU) 320 is also connected to theinput/output port 330, and sends control signals to the driving circuits121.1, 121.2, 121.3, . . . , 121.i, . . . , 121.N through theinput/output port 330.

Specifically, the battery monitoring unit 310 monitors the states of allthe battery modules 101.1, 101.2, 101.3, . . . , 101.i, . . . , 101.Nthrough the monitoring circuits 141.1, 141.2, 141.3, . . . , 141.i, . .. , 141.N connected with the battery modules 101.1, 101.2, 101.3, . . ., 101.i, . . . , 101.N, and sends the monitored abnormal state signalsto the processor 320. In some embodiments, when the processor 320determines that a certain battery module 101.i, which is operating in anabnormal state, needs to be disconnected according to the monitoredabnormal state signals, the processor 320 transmits a disconnectingsignal to the corresponding driving circuit 121.i of the abnormalbattery module 101.i through the input/output port 330. Further, thedriving circuit 121.i can disconnect the abnormal battery module 101.iby directly connecting the series circuit through the bridge 203.i inthe connecting circuit 111.i. As an example, the processor (CPU) 320 ofthe present invention is an AT89S51 microcontroller, however, thepresent disclosure is not limited thereto.

FIG. 3B is a schematic diagram illustrating a structure of a drivingcircuit according to an embodiment of the disclosure.

As shown in FIG. 3B, for example, the driving circuit 121.i includes anauxiliary power supply 331.i, an NPN type triode 332.i, a relay 339.iand the like. In some embodiments, the relay 339.i is provided with acoil 337.i and an iron core 338.i. The triode 332.i is provided with acollector 334.i, a base 335.i and an emitter 336.i. One end of the coil337.i is connected with the auxiliary power supply 331.i, and the otherend of the coil 337.i is connected with the collector 334.i of thetriode 332.i. The base 335.i of the triode 332.i is connected to theoutput of the aforementioned input/output port 330, and the emitter336.i of the triode 332.i is grounded.

As mentioned above, when the series circuit of the battery pack 100operates in a normal state, the movable end of the first moving end205.i of the first switch 201.i of each connecting circuit 111.i isconnected to the positive terminal 208.i of the battery module 101.i.

Similarly, the movable end of the second moving end 207.i of the secondswitch 202.i is connected to the negative terminal 209.i of the batterymodule 101.i. As such, the battery module 101.i can be accordinglyconnected into the series circuit of the battery pack 100.

However, when the battery monitoring unit 310 detects that a certainbattery module 101.i is operating in an abnormal state and processer 320determines that the abnormally-battery module 101.i cannot be connectedto the series circuit any more, the processor 320 transmits a controlsignal (low current) to the base 335.i of the triode 332.i in thedriving circuit 121.i through the input/output port 330. When thecollector 334.i of the triode 332.i is connected with the emitter 336.i,a high current connection is formed between the auxiliary power supply331.i and the ground. At this time, the iron core 338.i may produce amagnetic force when the high current flows through the coil 337.i toattract the movable end points of the first moving end 205.i and thesecond moving end 207.i away from the positive terminal 208.i and thenegative terminal 209.i of the battery module 102.i, respectively (orpush away in other manners). The movable end points of the first movingend 205.i and the second moving end 207.i are then respectivelyconnected with the first end point 204.i and the second end point 206.iof the bridge 203.i. As such, the battery module 101.i is bypassed fromthe series circuit.

FIG. 4 is a schematic diagram illustrating the connecting circuits whena certain battery module of the battery pack fails, according to anembodiment of the disclosure. While any battery module may operate in anabnormal state, as a non-limiting example, the description of FIG. 4 isprovided using the situation where battery module 101.2 operates in anabnormal state. In some embodiments, when the battery monitoring unit310 detects that the battery module 101.2 is operating in an abnormalstate, the processor 320 determines whether the battery module 101.2needs to be disconnected based on a signal indicating the abnormal statereceived from the battery module 101.2. When the processor 320determines that the battery module 101.2 needs to be disconnected, theprocessor 320 transmits a disconnecting signal to the driving circuit121.2, so that the series circuit may bypass the battery module 101.2through the connecting circuit 111.2. Bypassing the battery module 101.2entails connecting the negative terminal 209.1 of the previous batterymodule 101.1 in the normal state to the positive terminal 208.3 of thesucceeding battery module 101.3 using the bridge 203.2, to connect theseries circuit of the battery pack 100.

Similarly, when the previous battery module 101.1, the succeedingbattery module 101.3, or any other battery module 101.i operates in anabnormal state, the abnormal battery module 101.i can be bypassed byadopting the above method through the corresponding connecting circuit111.i. As such, the normal battery modules 101.h and 101.k adjacent tothe abnormal battery module 101.i may be connected to each other by thecorresponding bridge 203.i.

In some embodiments, when the first battery module 101.1 and the lastbattery module 101.N in the battery pack 100 fail, the connectingcircuit 111.1 corresponding to the first battery module 101.1 directlyconnects the positive terminal of the battery pack 100 with the positiveterminal of the second battery module 101.2. Similarly, the connectingcircuit 111.N of the Nth battery module 101.N directly connects thenegative terminal of the battery pack 100 with the negative terminal ofthe (N−1)th battery module 101.(N−1).

Above described are exemplary methods for disconnecting a battery moduleoperating in an abnormal state in the battery pack, according toexamples of the disclosure. Further, exemplary structures forimplementing the method, according to embodiments of the disclosure, arealso described above. Whether a battery module operates in an abnormalstate may be determined by monitoring various working parameters of thebattery module. In some embodiments, whether a battery module isoperating in an abnormal state is determined by monitoring the workingvoltage V and the working temperature T of the battery module. Inaddition, whether the battery module, which operates in an abnormalstate, needs to be disconnected is determined according to the specificstate of the working voltage V and the working temperature T.

It should be noted that, besides the working voltage V and the workingtemperature T of the battery module, other working parameters of thebattery module can also be monitored to determine whether a batterymodule is operating in an abnormal state. Similarly, other workingparameters may be monitored to determine whether the abnormal batterymodule needs to be disconnected, which all fall into the protectionscope of the present disclosure.

In some embodiments, the lower limit of the working voltage of thebattery module is set at V_(bot1) and the upper limit of the workingtemperature is set at T_(top1). If the working voltage V is smaller thanV_(bot1) and/or the working temperature T is greater than T_(top1), itcan be determined that the battery module is operating in an abnormalstate. Further, by determining the specific abnormal conditions of thebattery modules using the working voltage V and the working temperatureT, the control device 130 can determine whether or not to disconnect thebattery module operating in the abnormal state. In addition, the controldevice 130 can also send different fault signals to a vehicle controlunit (VCU) to inform a vehicle operator of the emergency degree of abattery fault, so that the vehicle operator can take a correspondingfault processing strategy according to different fault signals.

FIG. 5 is a flow schematic diagram illustrating fault processingstrategies for an electric vehicle adopting the battery pack accordingto an embodiment of the disclosure and adopting the battery moduleabnormality judging methods described above.

At block 501, the battery monitoring unit 310 monitors the workingvoltage V and the working temperature T (e.g., V<V_(bot1) and/orT>T_(top1)) of the battery modules to determine whether a certainbattery module (e.g., battery module 101.i) is operating in an abnormalstate.

At block 502, the battery monitoring unit 310 sends a signal indicatingthat the battery module is operating in an abnormal state to theprocesser 320 when V<V_(bot1) and/or T>T_(top1), so that the processer320 can analyze and judge the signal.

At block 503, the processer 320 analyzes the state of the workingvoltage V of the battery module and the state of the working temperatureT of the battery module based on the received signal. When the workingvoltage V of the battery module is analyzed, the safety lower limit ofthe voltage of the battery module is set as V_(bot2). As such, thebattery module is determined to be in a state A if V_(bot1)>V>V_(bot2),and the battery module is determined to be in a state B if V<V_(bot2).

When the working temperature T of the battery module is analyzed, thesafe upper limit of the temperature of the battery module is set asT_(top2). As such, the battery module is determined to be in a state Cif T_(top2)>T>T_(top1), and the battery module is determined to be in astate D if T>T_(top2).

After the above analysis, the processer 320 determines the states of theworking voltage and the working temperature of the battery module todetermine whether to disconnect the battery module. Further, theprocessor 320 may determine which type of fault signal to transmit tothe vehicle operator based on the working voltage state and the workingtemperature state.

In some embodiments, if the battery module is in the state A or C, thenat block 505.1, the processor 320 determines that the battery module isoperating in an abnormal state, but an immediate danger is not present.

At block 506.1, the control device 130 determines not to disconnect theabnormally-operating battery module, but rather maintains the connectionof the abnormal battery module.

At block 507.1, the control device 130 informs a vehicle control system(VCU) to send out a signal warning the driver to visit a maintenancestation as early as possible, so as to maintain the fault batterymodule.

In some embodiments, if the battery module is in the state B, B and C, Aand C, A and D or D, at block 505.2, the processor 320 determines thatthe battery module is operating in an abnormal state and a potentialdanger exists.

At block 506.2, the control device 130 determines to disconnect theabnormal battery module.

At block 507.2, the control device 130 informs the vehicle controlsystem (VCU) to send out a signal warning the driver to visit amaintenance station immediately, so as to maintain the fault batterymodule.

In some embodiments, if the battery module is in the state B and D, atblock 505.3, the processor 320 determines that the battery module isoperating in an abnormal state and an immediate danger exists.

At block 506.3, the control device 130 determines to disconnect theabnormal battery module.

At block 507.3, the control device 130 informs the vehicle controlsystem (VCU) to send out a signal warning the driver to leave thevehicle immediately, so as to avoid an accident.

By adopting the fault processing strategies shown in FIG. 5, theelectric vehicle adopting the battery pack according to embodiments ofthe disclosure may provide advantages, such as ensuring the safety of adriver driving the electric vehicle and prolonging the service life ofthe battery.

Although the present disclosure has been described with reference to thespecific embodiments shown in the drawings, it should be understood thatthe lightweight fastening methods provided by the present disclosure canhave a variety of variations without departing the spirit, scope andbackground of the present disclosure. The description given above ismerely illustrative and is not meant to be an exhaustive list of allpossible embodiments, applications or modifications of the invention.Those of ordinary skill in the art should be still aware that,parameters in the embodiments disclosed by the present disclosure can bechanged in different manners, and these changes shall fall within thespirit and scope of the present disclosure and the claims. Thus, variousmodifications and variations of the described methods and systems of theinvention will be apparent to those skilled in the art without departingfrom the scope and spirit the invention.

What is claimed is:
 1. A battery pack in a vehicle, the battery packcomprising: a plurality of battery modules connected through aconnecting circuit, the plurality of battery modules including a firstbattery module; and a control device configured to selectivelydisconnect any one of the plurality of battery modules from theconnecting circuit, wherein: the control device is configured to obtaina first value for a first parameter for the first battery module; obtaina second value for a second parameter for the first battery module;determine whether the first battery module is in a first state based onthe first value and second value; determine whether the first batterymodule is in a second state based on the first value and second value;and when the first battery module is determined to be in the secondstate, generate instructions for removing the first battery module fromthe connecting circuits, and a warning message.
 2. The battery pack ofclaim 1, wherein: determine whether the first battery is in a thirdstate based on the first value and second value; and when the firstbattery module is determined to be in the third state, generateinstructions for removing the first battery module from the connectingcircuits, and a safety message.
 3. The battery pack of claim 1, whereineach battery module is provided with a positive terminal and a negativeterminal, and each connecting circuit comprises: a first switch; asecond switch; and a bridge, comprising a first end point and a secondend point, which are electrically connected with each other; and,wherein the first switch is caused to selectively connect or disconnectthe negative terminal of a second battery module in the plurality ofbattery modules with or from the positive terminal of the first batterymodule, and correspondingly disconnect or connect the negative terminalof the second battery module from or with the first end point of thebridge; and the second switch is caused to selectively connect ordisconnect the positive terminal of a third battery module in theplurality of battery modules with or from the negative terminal of thefirst battery module, and correspondingly disconnect or connect thepositive terminal of the third battery module from or with the secondend point of the bridge.
 4. The battery pack of claim 1, wherein thefirst parameter measures a working voltage for each of the batterymodules and the second parameter measures a working temperature for eachof the battery modules.
 5. The battery pack of claim 3, furthercomprising, a driving circuit configured to control connection states ofthe first switch and the second switch according to control signalstransmitted by the control device.
 6. The battery pack of claim 5,further comprising: monitoring circuits, which are respectivelyconnected with the plurality of battery modules, and configured tomonitor working states of the plurality of battery modules and transmitmonitoring signals to the control device; and a battery monitoring unitprovided within the control device and configured to receive themonitoring signals of the monitoring circuits and analyze the monitoringsignals, wherein the control device controls the plurality of drivingcircuits according to a determination result of the battery monitoringsystem with respect to the working states of the battery modules.
 7. Thebattery pack of claim 4, wherein, when the working voltage V of thefirst battery module is less than a lower limit Vbot1 or the workingtemperature T is greater than an upper limit Ttop1, the batterymonitoring unit determines that the first battery module is operating inthe abnormal state, and transmits a signal indicating the abnormal stateto a processor for analysis; and, wherein the processor is configured toanalyze a working voltage state and a working temperature state of thefirst battery module to determine whether to disconnect the firstbattery module operating in the abnormal state and transmit one or morefault signals to a vehicle control unit (VCU); wherein, when theprocessor analyzes the working voltage state of the current batterymodule, the working voltage V of the current battery module is comparedwith a safety lower limit Vbot2, the first battery module is determinedto be in a state A if Vbot1>V>Vbot2, and the first battery module isdetermined to be in a state B if V<Vbot2; when the processor analyzesthe working temperature state of the first battery module, the workingtemperature T of the battery module is compared with a safety upperlimit Ttop2, the first battery module is determined to be in a state Cif Ttop2>T>Ttop1, and the first battery module is determined to be in astate D if T>Ttop2; when the processor determines that the first batterymodule is in the state A or C, the processor determines that the firstbattery module is operating in the abnormal state without an immediatedanger, and determines not to disconnect the first battery module,maintains the connection of the first battery module, and transmits afault signal of warning a driver to drive to a maintenance station asearly as possible to the VCU; when the processor determines that thefirst battery module is in the state B, B and C, A and C, A and D, or D,the processor determines that the current battery module is operating inthe abnormal state with a potential danger, and disconnects the currentbattery module, and transmits a fault signal of warning the driver todrive to the maintenance station immediately to the VCU; and when theprocessor determines that the first battery module is in the state B andD, the processor determines that the current battery module is operatingin the abnormal state with an immediate danger, and disconnects theabnormal battery module, and transmits a fault signal of warning thedriver to leave the vehicle immediately to the VCU.
 8. A method ofcontrolling a vehicle battery pack having a plurality of battery modulesconnected through connecting circuits, the plurality of battery modulesincluding a first battery module, each battery module connected to aconnecting circuit, said method comprising: monitoring multiple workingparameters of the battery modules, the working parameters including afirst parameter and a second parameter; receive a first value of thefirst parameter for the first battery module; receive the secondparameter for the first battery module from the battery monitoring unit;determine whether the first battery module is in a first state based onthe first value and second value; determine whether the first batterymodule is in a second state based on the first value and second value;when the first battery module is determined to be in the second state,generate instructions for removing the first battery module from theconnecting circuits, and a warning message.
 9. The method of claim 8,wherein each battery module is provided with a positive terminal and anegative terminal, and each connecting circuit comprises: a firstswitch; a second switch; a bridge, comprising a first end point and asecond end point, which are electrically connected with each other;wherein said disconnecting includes: in the connecting circuit of thefirst battery module selectively disconnecting, by the first switch, anegative terminal of a second battery module in the plurality of batterymodules from a positive terminal of the first battery module, andconnecting, by the first switch, a negative terminal of the secondbattery module with the first end point of the bridge, and selectivelydisconnecting, by the second switch, a positive terminal of a thirdbattery module in the plurality of battery modules from the negativeterminal of the first battery module, and connecting, by the secondswitch, a positive terminal of the third battery module with the secondend point of the bridge.
 10. The method of claim 8, further comprisingdetermining whether the first battery is in a third state based on thefirst value and second value; and when the first battery module isdetermined to be in the third state, generate instructions for removingthe first battery module from the connecting circuits, and a safetymessage.
 11. The method of claim 10, further comprising controlling, bya driving circuit of the plurality of driving circuits, connectionstates of the first switch and the second switch according to thecontrol signals transmitted by the control device.
 12. The method ofclaim 11, further comprising: monitoring working states of the pluralityof battery modules via monitoring circuits respectively connected withthe plurality of battery modules; transmitting monitoring signals fromthe monitoring circuits to the control device; receiving the monitoringsignals at a battery monitoring unit provided within the control device;analyzing the monitoring signals via the battery monitoring unit; andcontrolling the plurality of driving circuits via the control deviceaccording to a determination result of the battery monitoring unit withrespect to the working states of the battery modules.
 13. The method ofclaim 12, wherein, the first parameter includes a working voltage V andthe second parameter includes a working temperature T of the pluralityof battery modules, and wherein when the working voltage V of the firstbattery module is less than a lower limit Vbot1 or the workingtemperature T is greater than an upper limit Ttop1, the method comprisesdetermining that the first battery module is operating in the abnormalstate, and transmitting a signal indicating the abnormal state to aprocessor of the control device.
 14. The method of claim 13, furthercomprising: analyzing the working voltage state and the workingtemperature state of the first battery module to determine whether todisconnect the current battery module operating in the abnormal stateand transmit one or more fault signals to a vehicle control unit (VCU);wherein, analyzing the working voltage state of the first battery modulecomprises comparing the working voltage V of the first battery modulewith a safety lower limit Vbot2, and determining the first batterymodule to be in a state A if Vbot1>V>Vbot2, and to be in a state B ifV<Vbot2; and analyzing the working temperature state of the firstbattery module comprises comparing the working temperature T of thebattery module with a safety upper limit Ttop2, determining the firstbattery module to be in a state C if Ttop2>T>Ttop1, and determining thefirst battery module to be in a state D if T>Ttop2.